Hitachi SR-2000

The SR-2000, SR-2000L, and SR-2001 were a group of AM-FM Stereo Receiver Amplifiers manufactured in Japan by the Hitachi Corporation in approximately 1981. They were 25-watts per channel amplifiers based on the Sanyo STK463 Hybrid power amplifier module. The SR-2000L was a model with long wave band, medium wave band, and FM. However, the SR-2000, and SR-2001, had only medium wave band and FM. The SR-2001 was a 120 V model for the US market. Its top cover was usually metal with a wood grain paint effect, and the back panel usually had an un-switched 2-pin mains output socket. The photographs in this multi page article are of the SR-2000L.

Review

The Sanyo STK463 was one of the nicest sounding hybrid power amplifiers, and even today very few modern amplifiers can match the sound quality that it had. Many early amplifiers with this hybrid IC were straight analogue systems producing a smooth bass and very sharp treble response and consequently were highly desirable. This amplifier also has a built in RIAA preamplifier for connecting a record player/turntable and consequently many audiophiles find it invaluable. The RIAA equaliser circuit has ±0.5 dB deviation, and input sensitivity of 2.5 mV (46 kΩ).

The tuner design is high spec boasting features such as vector tuning that consists of two illuminated arrows, which display the direction the user must move the tuning needle. Inside, it has a large open plate tuning capacitor, and first-class radio circuitry that performs well. Looking at the tuner circuitry, I noticed that the FM front-end uses the 2SK55 FET input, whilst the AM front-end uses the 2SK104 FET input. This is one of the reasons why the FM circuit has 5.5 µV sensitivity in stereo, and the AM circuit has 15 µV sensitivity.

The amplifier also has interesting specifications such as a Baxandall bass and treble circuit producing 10 dB boost and cut for the bass (100 Hz), and 8 dB boost and cut for the treble (10 kHz). The loudness control circuit produces a further +9 dB boost at 100 Hz, which on a low volume gives that lovely creamy bass that people like. With a good pair of loudspeakers and a turntable, this amplifier will certainly give a high degree of owner satisfaction.

Price/eBay

The SR-2000, SR-2000L, and SR-2001 are very desirable vintage amplifiers that are often for sale on eBay. Anything with an STK series hybrid usually sounds good because of its precise hi-fi sound and that is why people are willing to pay extra for it. Unfortunately, Sanyo stopped producing these hybrid modules many years ago and therefore any old stock is going to become more expensive over the years including amplifiers that have these in them. An amplifier in good working mint condition can sell for well over fifty pounds and more.

A burnt amplifier is usually not worth much because the replacement hybrid module is expensive, and it is a time-consuming job to install it into the amplifier. However many owners are willing to pay the premium and have their amplifiers repaired, because where else will they find another amp that sounds as good as this?

This Article Continues...